Method of treating shoe stiffener blanks



X. R. SCHOENKY 1,775,143

METHOD OF TREATING SHOE STIFFENER BLANKS Filed Nov. 19, 1928 A fi i Patented Sept. 9, 1930 UNITED STATES PATENT OFFICE AUGUST R. SGHOENKY, OF BEVERLY, MASSACHUSETTS, ASSIGNOB TO THE OELABTIC OORIPORATION, OI WILMINGTON, DELAWARE, A CORPORATION 01 DELAWARE METHOD OF TREATING SHOE STII'FENEB BLANKB Application filed November 19, 1928. Serial 110.320,!88.

This invention relates to a method of treating stiffener blanks for parts of boots and shoes and is herein described with particular reference to treating toe stiffener blanks.

5 In the manufacture of shoes, it is customary to employ a toe stiffener to aid in imparting the desired sha e to the ,toe portion of the upper of the slioe and in maintaining this desired shape. In the case of plain-toad o shoes,'which have no toe cap or tip, it is customary to use a so-called soft box toe stiffener, that is, one without much stiffness or resilience. A stiffener for use in such shoes should have a comparativel soft rear margin since otherwise a ridge or reak will appear across the toe portion of the upper in register with,the rear edge of the stiffener after the shoe has been subjected to a short period of wear. The whole upper portion of the stiffener should also be comparatively soft,

that is, it should have only just enough resilience to maintain the desired shape in the adjacent portion of the up er; but the front wall of the stiifeneF-or 0th the front and side wallsshould be comparatively stiif so as to furnish a firm foundation, so to s eak, for the softer upper portion of the sti ener.

According to the method of the present invention, an absorbent stiffener blank is first treated in a manner to reduce its absorptivity in the-locality in, which the finished stiffener should be soft, and is then treated with a liquid which is absorbed wholly or principally in the locality in which the finished stiffener should be comparatively hard.

The illustrated stiffener blank is of that type which comprises a base of sheet material impregnated with a precipitated colloid, the colloid in its precipitated form imparting very little stiffness to the blank. Such blanks are dipped in a solvent for the colloid, incorporated in the upper of a shoe, conformed to the toe portion of the last while wet and limp and allowed to stand until the solvent evaporates, the colloid emerging from its solution in a horny or filmy form which is stiff and resilient. In accordance with the present invention, as herein exemplified, in order to prevent any considerable amount of the solvent from being absorbed by that portion of the blank which is to form the upper part of the stifiener in the finished shoe, that portion of the blank is compressed so as to reduce its absor tivity before the blank is treated with the solvent. Most of the colloid in this portion, therefore, remains in its precipitated form in which it imparts very little stiffness to the stiffener while the remaining colloid is changed into its horny form to provide stiff front and side portions.

Referring to the accompanying drawings, I Fig. 1 is a plan view of a stiflener blank after it has been compressed in the selected locality, and

Fig. 2 is a section on a greatly enlarged scale on the line 22 of Fig. 1.

The illustrated stiffener blank is of the type disclosed in United States Letters PatentNo. 1,256,240 granted February 12, 1918 upon an application filed in the name of Stanley P. Lovell. Blanks of this type consist of a base of felt or woven fabric in which a colloidal substance, such, for example,.as celluloid, has been precipitated. The blank in this'state has comparatively little resilience. When, however, the blank is immersed ina solvent for the colloidal substance (for example alcohol, if the colloid is celluloid) and then allowed to stand until the solvent evaporates. the colloidal substance is changed over to its horny or filmy form in which it is strong and resilient.

The blank in its original state has about the de ree of resilience desired for the portion 0 the blank which, in the finished shoe, should be comparatively soft. This portion, indicated at 3 and bounded by the rear edge 5 of the blank and a marginal zone 7 extending along the front and side edges of the blank, is therefore compressed. A more or less diagrammatic representation of what is believed to result from the compression is indicated in Fig. 2. In the uncompressed portion 7 of the blank the particles 9 of the precipitated colloidal substance are more or less spaced from one another. At any rate the substance is porous so that it will readily absorb a solvent. In the compressed portion, on the other hand, the particles of the colloidal substance have been squeezed together to front and side portion.

i or to the particular sort of liquid which has such an extent that the absorptivity of the substance in that locality has been greatly reduced. Consequently, when the blank is dipped momentarily in a solvent, very little if any of the solvent is absorbed by the portion 3, but the portion 7 is almost instantly saturated. The blank is then incorporated in the upper of a shoe and conformed to the toe portion of the last during the pulling over and lasting operations; and, when the solvent has evaporated, there results in the finished shoe :1 box toe stiiiener having a soft upper portion and a comparatively stiflf and resilient In order to promote brevity, the method has been described with reference to the compression of a portion of a blank and the subsequent treatment of the blank with a solvent liquid. It should be understood, however, that the method, in its broader aspects, is not limited to the use of compression to reduce absorptivity, to the particular sort of blank been described.

Having thus-described my invention, what I claim as new and desired to secure by Let-- then treating the blank with a liquid whereby the liquid is absorbed in diflere'nt quantities per unit volume of the blank in different localities.

' 3. The method of treating an absorbent'box toe blank which comprises reducing the absorptivity of the blank in its middle and rear portions and then treating the blank with a liquid. l l

4. The method of treating an absorbent box toe blank whichcomprise's compressing the blank in its middle and rear portions and then treating the blank with a liquid.

5. The method of treating an absorbent box toe blank which comprises reducing the absorptivity of the blank ina locality bounded by the rear edge of the blank and a zone extending alon the margin at the front and sides of the blank and then subjecting the blank to the action of a liquid.

6. The method of treating an absorbent shoe stiffener blank containing a stiffening substance in a porous absorptive state which comprises reducing the absorptivity of the stiffening substance in a selected locality of the blankand then treating the blank with a liquid which tends to soften the stifiening substance.

7. The method of treating an absorbent shoe stifi'ener blank containing a-stifi'enin substance in a porous absorptive state whic comprises compressing the' stiflfening substance in a selected locality of the blank and then treating the blank with a liquid which tends to soften the stiffening substance.

. 8. The method of treating an absorptive shoestiflener blank containing a precipitated colloidal stiffening substance which comprises compressing the blank in a selected locality and then treatin the blank with a solvent for the colloidal su stance.

9. A step-product consisting of an absorbent shoe stiffener blank, having a given o density throughout a zone extending along a margin of the blank andhaving a greater density throughout the remaining portions of the blank.

In testimony whereof'I have signed my name to this specification. a AUGUST R. SGHOENKY. 

